A common operation for buffing various surfaces was to first use a commercially available wool or foam cleaning surface to remove imperfections from the surface, and to then switch to a foam surface for final polishing operation.
More particularly, when repainting or refinishing a surface such as a panel of an automobile or the like, it is common practice to remove imperfections such as dust nibs, runs and sags using ultra-fine sandpaper. This, however, leaves fine sandpaper scratches which give the painted finish a dull look. The current practice to remove these sandpaper scratches is to first clean (also know as compounding, removing or cutting) the scratched area by use of a rubbing compound and a cleaning surface such as a sheepskin mounted on a powered polishing tool. This requires that substantial and well-distributed pressure be applied to the cleaning surface and that a significant amount of material be removed from the work surface. The operation is then completed by polishing the cleaned area as with a foam polishing surface. Heretofore, in usual practice, two separate polishing tools were inter changeable used or the cleaning surface was removed from the polishing tool and replaced with a polishing surface. The constant changing was undesirable for various reasons including cost and inefficiency.
U.S. Pat. No. 5,389,032 by Beardsley discloses one attempt to provide for this need. It discloses an abrasive article which has a pair of concentric abrasive surfaces, a circular inner surface or layer 28 recessed back from a ring-shaped annular outer surface or layer 24. As shown in the drawings, inner layer 28 is affixed to a thinner circular inner support portion 22 of a less compressible material, and annular outer layer 24 is affixed to an annular thicker outer support portion 20 of a more compressible material. Both support portions 20, 22 are affixed to a pad 12 represented in the drawings as a porous or foam or material. The pad 12 includes means for connecting to an abrading apparatus 18. That connecting means appears in the drawings to constitute a plate of metal or other solid material that extends fully across the rear surface of the foam pad 12.
While such a continuous flat plate extending across the full width may operate satisfactorily for some applications, it has been found by applicant that such a structural arrangement will not concentrate force on a central inner cleaning surface so as to provide efficient removal or cleaning away when there is a desire to remove significant amounts of material from a work surface.